/diy/ - Do It Yourself

How do I make a circuit that gets the charge level from a battery and outputs it to a percentage via graphical display?
I've tried hunting around online and most circuits are just using op amp comparators for some predermined percentage value. Which is fine, if I only wanted to show like 5 states. I want it to be accurate to down to at least 1%.
I know charge level has to do with the voltage output of a battery. Do I just find the max & min voltage level and extrapolate the rest in between?
I would like to make something with discrete components if the footprint doesn't end up being too large. Otherwise if there's an IC that can do this.